Many modern systems and devices employ user authorization techniques to prevent access/use by unauthorized users and potentially to restrict access/use by certain authorized users. For example, many computer systems and computer applications perform user identification requiring a user to enter a username and password to gain authorized access to the system or application. Similarly, some electronic devices perform user identification requiring a user to enter an access code or other identification information to be authorized to use the device. These user authorization techniques are similar in that they require the user to perform some separate user identification operation (e.g., username and password entry, access code entry, etc.) distinct from the user's normal operation of the underlying system, application, device, etc. Furthermore, conventional user authorization techniques based on biometrics typically also can require the user to perform some separate user identification operation (e.g., speaking an access phrase into the microphone, placing a finger on the fingerprint reader, etc.). Conventional biometric user authorization techniques may further require the inclusion of special input component(s) (e.g., such as a microphone for voice analysis, a fingerprint reader for fingerprint analysis, etc.) in addition to the standard input component(s) already present and used by the underlying system, application, device, etc.